[BZ #2423]

2006-03-07  Jakub Jelinek  <jakub@redhat.com>
	[BZ #2423]
	* math/libm-test.inc [TEST_LDOUBLE] (ceil_test, floor_test, rint_test,
	round_test, trunc_test): Only run some of the new tests if
	LDBL_MANT_DIG > 100.

2006-03-03  Steven Munroe  <sjmunroe@us.ibm.com>
	    Alan Modra  <amodra@bigpond.net.au>

	* sysdeps/powerpc/fpu/fenv_libc.h (__fegetround, __fesetround):
	Define inline implementations.
	* sysdeps/powerpc/fpu/fegetround.c: Use __fegetround.
	* sysdeps/powerpc/fpu/fesetround.c: Use __fesetround.

	* sysdeps/powerpc/fpu/math_ldbl.h: New file.

	[BZ #2423]
	* math/libm-test.inc [TEST_LDOUBLE] (ceil_test, floor_test, rint_test,
	round_test, trunc_test): Add new tests.
	* sysdeps/ieee754/ldbl-128ibm/math_ldbl.h
	(EXTRACT_IBM_EXTENDED_MANTISSA, INSERT_IBM_EXTENDED_MANTISSA):
	Removed, replaced with ...
	(ldbl_extract_mantissa, ldbl_insert_mantissa, ldbl_pack, ldbl_unpack,
	ldbl_canonicalise, ldbl_nearbyint): New functions.
	* sysdeps/ieee754/ldbl-128ibm/e_fmodl.c (__ieee754_fmodl): Replace
	EXTRACT_IBM_EXTENDED_MANTISSA and INSERT_IBM_EXTENDED_MANTISSA
	with ldbl_extract_mantissa and ldbl_insert_mantissa.
	* sysdeps/ieee754/ldbl-128ibm/e_rem_pio2l.c (__ieee754_rem_pio2l):
	Replace EXTRACT_IBM_EXTENDED_MANTISSA with ldbl_extract_mantissa.
	(ldbl_extract_mantissa, ldbl_insert_mantissa): New inline functions.
	* sysdeps/ieee754/ldbl-128ibm/s_ceill.c (__ceill): Handle rounding
	that spans doubles in IBM long double format.
	* sysdeps/ieee754/ldbl-128ibm/s_floorl.c: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_rintl.c: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_roundl.c: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_truncl.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_rintl.S: File removed.

8 files changed, 446 insertions, 490 deletions

diff --git a/sysdeps/ieee754/ldbl-128ibm/e_fmodl.c b/sysdeps/ieee754/ldbl-128ibm/e_fmodl.c
index 96668735b1..e99b0bac34 100644
--- a/sysdeps/ieee754/ldbl-128ibm/e_fmodl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/e_fmodl.c
@@ -76,8 +76,8 @@ static long double one = 1.0, Zero[] = {0.0, -0.0,};
     /* Make the IBM extended format 105 bit mantissa look like the ieee854 112
        bit mantissa so the following operatations will give the correct
        result.  */
-        EXTRACT_IBM_EXTENDED_MANTISSA(hx, lx, temp, x);
-        EXTRACT_IBM_EXTENDED_MANTISSA(hy, ly, temp, y);
+        ldbl_extract_mantissa(&hx, &lx, &temp, x);
+        ldbl_extract_mantissa(&hy, &ly, &temp, y);
 
     /* set up {hx,lx}, {hy,ly} and align y to x */
 	if(ix >= -1022)
@@ -127,7 +127,7 @@ static long double one = 1.0, Zero[] = {0.0, -0.0,};
 	    iy -= 1;
 	}
 	if(iy>= -1022) {	/* normalize output */
-	    INSERT_IBM_EXTENDED_MANTISSA(x, (sx>>63), iy, hx, lx);
+	    x = ldbl_insert_mantissa((sx>>63), iy, hx, lx);
 	} else {		/* subnormal output */
 	    n = -1022 - iy;
 	    if(n<=48) {
@@ -138,7 +138,7 @@ static long double one = 1.0, Zero[] = {0.0, -0.0,};
 	    } else {
 		lx = hx>>(n-64); hx = sx;
 	    }
-	    INSERT_IBM_EXTENDED_MANTISSA(x, (sx>>63), iy, hx, lx);
+	    x = ldbl_insert_mantissa((sx>>63), iy, hx, lx);
 	    x *= one;		/* create necessary signal */
 	}
 	return x;		/* exact output */
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_rem_pio2l.c b/sysdeps/ieee754/ldbl-128ibm/e_rem_pio2l.c
index 416547c220..8b1c976f3b 100644
--- a/sysdeps/ieee754/ldbl-128ibm/e_rem_pio2l.c
+++ b/sysdeps/ieee754/ldbl-128ibm/e_rem_pio2l.c
@@ -199,7 +199,8 @@ int32_t __ieee754_rem_pio2l(long double x, long double *y)
 {
   long double z, w, t;
   double tx[8];
-  int64_t exp, n, ix, hx, ixd;
+  int exp;
+  int64_t n, ix, hx, ixd;
   u_int64_t lx, lxd;
 
   GET_LDOUBLE_WORDS64 (hx, lx, x);
@@ -243,7 +244,7 @@ int32_t __ieee754_rem_pio2l(long double x, long double *y)
      stored in a double array.  */
   /* Make the IBM extended format 105 bit mantissa look like the ieee854 112
      bit mantissa so the next operatation will give the correct result.  */
-  EXTRACT_IBM_EXTENDED_MANTISSA (ixd, lxd, exp, x);
+  ldbl_extract_mantissa (&ixd, &lxd, &exp, x);
   exp = exp - 23;
   /* This is faster than doing this in floating point, because we
      have to convert it to integers anyway and like this we can keep
diff --git a/sysdeps/ieee754/ldbl-128ibm/math_ldbl.h b/sysdeps/ieee754/ldbl-128ibm/math_ldbl.h
index e7e1b963e8..d055d6597e 100644
--- a/sysdeps/ieee754/ldbl-128ibm/math_ldbl.h
+++ b/sysdeps/ieee754/ldbl-128ibm/math_ldbl.h
@@ -3,122 +3,179 @@
 #endif
 
 #include <sysdeps/ieee754/ldbl-128/math_ldbl.h>
+#include <ieee754.h>
+  
+static inline void
+ldbl_extract_mantissa (int64_t *hi64, u_int64_t *lo64, int *exp, long double x)
+{
+  /* We have 105 bits of mantissa plus one implicit digit.  Since
+     106 bits are representable we use the first implicit digit for
+     the number before the decimal point and the second implicit bit
+     as bit 53 of the mantissa.  */
+  unsigned long long hi, lo;
+  int ediff;
+  union ibm_extended_long_double eldbl;
+  eldbl.d = x;
+  *exp = eldbl.ieee.exponent - IBM_EXTENDED_LONG_DOUBLE_BIAS;
 
-#define EXTRACT_IBM_EXTENDED_MANTISSA(hi64, lo64, expnt, ibm_ext_ldbl) \
-  do									      \
-    {									      \
-      /* We have 105 bits of mantissa plus one implicit digit.  Since	      \
-	 106 bits are representable without the rest using hexadecimal	      \
-	 digits we use only the implicit digits for the number before	      \
-	 the decimal point.  */						      \
-      unsigned long long hi, lo;					      \
-      int ediff;							      \
-      union ibm_extended_long_double eldbl;				      \
-      eldbl.d = ibm_ext_ldbl;						      \
-      expnt = eldbl.ieee.exponent - IBM_EXTENDED_LONG_DOUBLE_BIAS;	      \
-									      \
-      lo = ((long long)eldbl.ieee.mantissa2 << 32) | eldbl.ieee.mantissa3;    \
-      hi = ((long long)eldbl.ieee.mantissa0 << 32) | eldbl.ieee.mantissa1;    \
-      /* If the lower double is not a denomal or zero then set the hidden     \
-	 53rd bit.  */							      \
-      if (eldbl.ieee.exponent2 > 0x001)					      \
-	{								      \
-	  lo |= (1ULL << 52);						      \
-	  lo = lo << 7; /* pre-shift lo to match ieee854.  */		      \
-          /* The lower double is normalized separately from the upper.  We    \
-	     may need to adjust the lower manitissa to reflect this.  */      \
-	  ediff = eldbl.ieee.exponent - eldbl.ieee.exponent2;		      \
-	  if (ediff > 53)						      \
-	    lo = lo >> (ediff-53);					      \
-	}								      \
-      hi |= (1ULL << 52);						      \
-  									      \
-      if ((eldbl.ieee.negative != eldbl.ieee.negative2)			      \
-	  && ((eldbl.ieee.exponent2 != 0) && (lo != 0LL)))		      \
-	{								      \
-	  hi--;								      \
-	  lo = (1ULL << 60) - lo;					      \
-	  if (hi < (1ULL << 52))					      \
-	    {								      \
-	      /* we have a borrow from the hidden bit, so shift left 1.  */   \
-	      hi = (hi << 1) | (lo >> 59);				      \
-	      lo = 0xfffffffffffffffLL & (lo << 1);			      \
-	      expnt--;							      \
-	    }								      \
-	}								      \
-      lo64 = (hi << 60) | lo;						      \
-      hi64 = hi >> 4;							      \
-    }									      \
-  while (0)
+  lo = ((long long)eldbl.ieee.mantissa2 << 32) | eldbl.ieee.mantissa3;
+  hi = ((long long)eldbl.ieee.mantissa0 << 32) | eldbl.ieee.mantissa1;
+  /* If the lower double is not a denomal or zero then set the hidden
+     53rd bit.  */
+  if (eldbl.ieee.exponent2 > 0x001)
+    {
+      lo |= (1ULL << 52);
+      lo = lo << 7; /* pre-shift lo to match ieee854.  */
+      /* The lower double is normalized separately from the upper.  We
+	 may need to adjust the lower manitissa to reflect this.  */
+      ediff = eldbl.ieee.exponent - eldbl.ieee.exponent2;
+      if (ediff > 53)
+	lo = lo >> (ediff-53);
+    }
+  hi |= (1ULL << 52);
+  
+  if ((eldbl.ieee.negative != eldbl.ieee.negative2)
+      && ((eldbl.ieee.exponent2 != 0) && (lo != 0LL)))
+    {
+      hi--;
+      lo = (1ULL << 60) - lo;
+      if (hi < (1ULL << 52))
+	{
+	  /* we have a borrow from the hidden bit, so shift left 1.  */
+	  hi = (hi << 1) | (lo >> 59);
+	  lo = 0xfffffffffffffffLL & (lo << 1);
+	  *exp = *exp - 1;
+	}
+    }
+  *lo64 = (hi << 60) | lo;
+  *hi64 = hi >> 4;
+}
 
-#define INSERT_IBM_EXTENDED_MANTISSA(ibm_ext_ldbl, sign, expnt, hi64, lo64) \
-  do									      \
-    {									      \
-      union ibm_extended_long_double u;					      \
-      unsigned long hidden2, lzcount;					      \
-      unsigned long long hi, lo;					      \
-									      \
-      u.ieee.negative = sign;						      \
-      u.ieee.negative2 = sign;						      \
-      u.ieee.exponent = expnt + IBM_EXTENDED_LONG_DOUBLE_BIAS;		      \
-      u.ieee.exponent2 = expnt-53 + IBM_EXTENDED_LONG_DOUBLE_BIAS;	      \
-      /* Expect 113 bits (112 bits + hidden) right justified in two longs.    \
-	 The low order 53 bits (52 + hidden) go into the lower double */      \
-      lo = (lo64 >> 7)& ((1ULL << 53) - 1);				      \
-      hidden2 = (lo64 >> 59) &  1ULL;					      \
-      /* The high order 53 bits (52 + hidden) go into the upper double */     \
-      hi = (lo64 >> 60) & ((1ULL << 11) - 1);				      \
-      hi |= (hi64 << 4);						      \
-  									      \
-      if (lo != 0LL)							      \
-	{								      \
-	  /* hidden2 bit of low double controls rounding of the high double.  \
-	     If hidden2 is '1' then round up hi and adjust lo (2nd mantissa)  \
-	     plus change the sign of the low double to compensate.  */	      \
-	  if (hidden2)							      \
-	    {								      \
-	      hi++;    							      \
-	      u.ieee.negative2 = !sign;					      \
-	      lo = (1ULL << 53) - lo;					      \
-	    }								      \
-	  /* The hidden bit of the lo mantissa is zero so we need to	      \
-	     normalize the it for the low double.  Shift it left until the    \
-	     hidden bit is '1' then adjust the 2nd exponent accordingly.  */  \
-									      \
-	  if (sizeof (lo) == sizeof (long))				      \
-	    lzcount = __builtin_clzl (lo);				      \
-	  else if ((lo >> 32) != 0)					      \
-	    lzcount = __builtin_clzl ((long) (lo >> 32));		      \
-	  else								      \
-	    lzcount = __builtin_clzl ((long) lo) + 32;			      \
-	  lzcount = lzcount - 11;					      \
-	  if (lzcount > 0)						      \
-	    {								      \
-	      int expnt2 = u.ieee.exponent2 - lzcount;			      \
-	      if (expnt2 >= 1)						      \
-		{							      \
-		  /* Not denormal.  Normalize and set low exponent.  */	      \
-		  lo = lo << lzcount; 					      \
-		  u.ieee.exponent2 = expnt2;				      \
-		}							      \
-	      else							      \
-		{							      \
-		  /* Is denormal.  */					      \
-		  lo = lo << (lzcount + expnt2);			      \
-		  u.ieee.exponent2 = 0;					      \
-		}							      \
-	    }								      \
-	}								      \
-      else 								      \
-	{								      \
-	  u.ieee.negative2 = 0;						      \
-	  u.ieee.exponent2 = 0;						      \
-	}								      \
-  									      \
-      u.ieee.mantissa3 = lo & ((1ULL << 32) - 1);			      \
-      u.ieee.mantissa2 = (lo >> 32) & ((1ULL << 20) - 1);		      \
-      u.ieee.mantissa1 = hi & ((1ULL << 32) - 1);			      \
-      u.ieee.mantissa0 = (hi >> 32) & ((1ULL << 20) - 1);		      \
-      ibm_ext_ldbl = u.d;						      \
-    }									      \
-  while (0)
+static inline long double
+ldbl_insert_mantissa (int sign, int exp, int64_t hi64, u_int64_t lo64)
+{
+  union ibm_extended_long_double u;
+  unsigned long hidden2, lzcount;
+  unsigned long long hi, lo;
+
+  u.ieee.negative = sign;
+  u.ieee.negative2 = sign;
+  u.ieee.exponent = exp + IBM_EXTENDED_LONG_DOUBLE_BIAS;
+  u.ieee.exponent2 = exp-53 + IBM_EXTENDED_LONG_DOUBLE_BIAS;
+  /* Expect 113 bits (112 bits + hidden) right justified in two longs.
+     The low order 53 bits (52 + hidden) go into the lower double */ 
+  lo = (lo64 >> 7)& ((1ULL << 53) - 1);
+  hidden2 = (lo64 >> 59) &  1ULL;
+  /* The high order 53 bits (52 + hidden) go into the upper double */
+  hi = (lo64 >> 60) & ((1ULL << 11) - 1);
+  hi |= (hi64 << 4);
+
+  if (lo != 0LL)
+    {
+      /* hidden2 bit of low double controls rounding of the high double.
+	 If hidden2 is '1' then round up hi and adjust lo (2nd mantissa)
+	 plus change the sign of the low double to compensate.  */
+      if (hidden2)
+	{
+	  hi++;
+	  u.ieee.negative2 = !sign;
+	  lo = (1ULL << 53) - lo;
+	}
+      /* The hidden bit of the lo mantissa is zero so we need to
+	 normalize the it for the low double.  Shift it left until the
+	 hidden bit is '1' then adjust the 2nd exponent accordingly.  */ 
+
+      if (sizeof (lo) == sizeof (long))
+	lzcount = __builtin_clzl (lo);
+      else if ((lo >> 32) != 0)
+	lzcount = __builtin_clzl ((long) (lo >> 32));
+      else
+	lzcount = __builtin_clzl ((long) lo) + 32;
+      lzcount = lzcount - 11;
+      if (lzcount > 0)
+	{
+	  int expnt2 = u.ieee.exponent2 - lzcount;
+	  if (expnt2 >= 1)
+	    {
+	      /* Not denormal.  Normalize and set low exponent.  */
+	      lo = lo << lzcount;
+	      u.ieee.exponent2 = expnt2;
+	    }
+	  else
+	    {
+	      /* Is denormal.  */
+	      lo = lo << (lzcount + expnt2);
+	      u.ieee.exponent2 = 0;
+	    }
+	}
+    }
+  else
+    {
+      u.ieee.negative2 = 0;
+      u.ieee.exponent2 = 0;
+    }
+
+  u.ieee.mantissa3 = lo & ((1ULL << 32) - 1);
+  u.ieee.mantissa2 = (lo >> 32) & ((1ULL << 20) - 1);
+  u.ieee.mantissa1 = hi & ((1ULL << 32) - 1);
+  u.ieee.mantissa0 = (hi >> 32) & ((1ULL << 20) - 1);
+  return u.d;
+}
+  
+/* Handy utility functions to pack/unpack/cononicalize and find the nearbyint
+   of long double implemented as double double.  */
+static inline long double
+ldbl_pack (double a, double aa)
+{
+  union ibm_extended_long_double u;
+  u.dd[0] = a;
+  u.dd[1] = aa;
+  return u.d;
+}
+
+static inline void
+ldbl_unpack (long double l, double *a, double *aa)
+{
+  union ibm_extended_long_double u;
+  u.d = l;
+  *a = u.dd[0];
+  *aa = u.dd[1];
+}
+
+
+/* Convert a finite long double to canonical form.
+   Does not handle +/-Inf properly.  */
+static inline void
+ldbl_canonicalize (double *a, double *aa)
+{
+  double xh, xl;
+
+  xh = *a + *aa;
+  xl = (*a - xh) + *aa;
+  *a = xh;
+  *aa = xl;
+}
+
+/* Simple inline nearbyint (double) function .
+   Only works in the default rounding mode
+   but is useful in long double rounding functions.  */
+static inline double
+ldbl_nearbyint (double a)
+{
+  double two52 = 0x10000000000000LL;
+
+  if (__builtin_expect ((__builtin_fabs (a) < two52), 1))
+    {
+      if (__builtin_expect ((a > 0.0), 1))
+	{
+	  a += two52;
+	  a -= two52;
+	}
+      else if (__builtin_expect ((a < 0.0), 1))
+	{
+	  a = two52 - a;
+	  a = -(a - two52);
+	}
+    }
+  return a;
+}
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_ceill.c b/sysdeps/ieee754/ldbl-128ibm/s_ceill.c
index a606548873..035e4f52ce 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_ceill.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_ceill.c
@@ -19,7 +19,7 @@
    02111-1307 USA.  */
 
 #include <math.h>
-#include <fenv.h>
+#include <fenv_libc.h>
 #include <math_ldbl_opt.h>
 #include <float.h>
 #include <ieee754.h>
@@ -34,87 +34,58 @@ __ceill (x)
      long double x;
 #endif
 {
-  static const double TWO52 = 4503599627370496.0L;
-  int mode = fegetround();
-  union ibm_extended_long_double u;
+  double xh, xl, hi, lo;
 
-  u.d = x;
+  ldbl_unpack (x, &xh, &xl);
 
-  if (fabs (u.dd[0]) < TWO52)
+  /* Return Inf, Nan, +/-0 unchanged.  */
+  if (__builtin_expect (xh != 0.0
+			&& __builtin_isless (__builtin_fabs (xh),
+					     __builtin_inf ()), 1))
     {
-      double high = u.dd[0];
-      fesetround(FE_UPWARD);
-      if (high > 0.0)
-	{
-	  high += TWO52;
-	  high -= TWO52;
-          if (high == -0.0) high = 0.0;
-	}
-      else if (high < 0.0)
-	{
-	  high -= TWO52;
-	  high += TWO52;
-          if (high == 0.0) high = -0.0;
-	}
-      u.dd[0] = high;
-      u.dd[1] = 0.0;
-      fesetround(mode);
-    }
-  else if (fabs (u.dd[1]) < TWO52 && u.dd[1] != 0.0)
-    {
-      double high, low;
-      /* In this case we have to round the low double and handle any
-         adjustment to the high double that may be caused by rounding
-         (up).  This is complicated by the fact that the high double
-         may already be rounded and the low double may have the
-         opposite sign to compensate.  */
-      if (u.dd[0] > 0.0)
-	{
-	  if (u.dd[1] > 0.0)
-	    {
-	      /* If the high/low doubles are the same sign then simply
-	         round the low double.  */
-	      high = u.dd[0];
-	      low = u.dd[1];
-	    }
-	  else if (u.dd[1] < 0.0)
-	    {
-	      /* Else the high double is pre rounded and we need to
-	         adjust for that.  */
-	      high = nextafter (u.dd[0], 0.0);
-	      low = u.dd[1] + (u.dd[0] - high);
-	    }
-          fesetround(FE_UPWARD);
-	  low += TWO52;
-	  low -= TWO52;
-          fesetround(mode);
-	}
-      else if (u.dd[0] < 0.0)
-	{
-	  if (u.dd[1] < 0.0)
-	    {
-	      /* If the high/low doubles are the same sign then simply
-	         round the low double.  */
-	      high = u.dd[0];
-	      low = u.dd[1];
-	    }
-	  else if (u.dd[1] > 0.0)
-	    {
-	      /* Else the high double is pre rounded and we need to
-	         adjust for that.  */
-	      high = nextafter (u.dd[0], 0.0);
-	      low = u.dd[1] + (u.dd[0] - high);
-	    }
-          fesetround(FE_UPWARD);
-	  low -= TWO52;
-	  low += TWO52;
-          fesetround(mode);
-	}
-      u.dd[0] = high + low;
-      u.dd[1] = high - u.dd[0] + low;
+      double orig_xh;
+      int save_round = fegetround ();
+
+      /* Long double arithmetic, including the canonicalisation below,
+	 only works in round-to-nearest mode.  */
+      fesetround (FE_TONEAREST);
+
+      /* Convert the high double to integer.  */
+      orig_xh = xh;
+      hi = ldbl_nearbyint (xh);
+
+      /* Subtract integral high part from the value.  */
+      xh -= hi;
+      ldbl_canonicalize (&xh, &xl);
+
+      /* Now convert the low double, adjusted for any remainder from the
+         high double.  */
+      lo = ldbl_nearbyint (xh);
+
+      /* Adjust the result when the remainder is non-zero.  nearbyint
+         rounds values to the nearest integer, and values halfway
+         between integers to the nearest even integer.  ceill must
+         round towards +Inf.  */
+      xh -= lo;
+      ldbl_canonicalize (&xh, &xl);
+
+      if (xh > 0.0 || (xh == 0.0 && xl > 0.0))
+	lo += 1.0;
+
+      /* Ensure the final value is canonical.  In certain cases,
+         rounding causes hi,lo calculated so far to be non-canonical.  */
+      xh = hi;
+      xl = lo;
+      ldbl_canonicalize (&xh, &xl);
+
+      /* Ensure we return -0 rather than +0 when appropriate.  */
+      if (orig_xh < 0.0)
+	xh = -__builtin_fabs (xh);
+
+      fesetround (save_round);
     }
 
-  return u.d;
+  return ldbl_pack (xh, xl);
 }
 
 long_double_symbol (libm, __ceill, ceill);
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_floorl.c b/sysdeps/ieee754/ldbl-128ibm/s_floorl.c
index 2be5e28698..4c4ae9b035 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_floorl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_floorl.c
@@ -19,7 +19,7 @@
    02111-1307 USA.  */
 
 #include <math.h>
-#include <fenv.h>
+#include <fenv_libc.h>
 #include <math_ldbl_opt.h>
 #include <float.h>
 #include <ieee754.h>
@@ -34,86 +34,52 @@ __floorl (x)
      long double x;
 #endif
 {
-  static const double TWO52 = 4503599627370496.0L;
-  int mode = fegetround();
-  union ibm_extended_long_double u;
+  double xh, xl, hi, lo;
 
-  u.d = x;
+  ldbl_unpack (x, &xh, &xl);
 
-  if (fabs (u.dd[0]) < TWO52)
+  /* Return Inf, Nan, +/-0 unchanged.  */
+  if (__builtin_expect (xh != 0.0
+			&& __builtin_isless (__builtin_fabs (xh),
+					     __builtin_inf ()), 1))
     {
-      double high = u.dd[0];
-      fesetround(FE_DOWNWARD);
-      if (high > 0.0)
-	{
-	  high += TWO52;
-	  high -= TWO52;
-          if (high == -0.0) high = 0.0;
-	}
-      else if (high < 0.0)
-	{
-	  high -= TWO52;
-	  high += TWO52;
-          if (high == 0.0) high = -0.0;
-	}
-      u.dd[0] = high;
-      u.dd[1] = 0.0;
-      fesetround(mode);
-    }
-  else if (fabs (u.dd[1]) < TWO52 && u.dd[1] != 0.0)
-    {
-      double high, low;
-      /* In this case we have to round the low double and handle any
-         adjustment to the high double that may be caused by rounding
-         (up).  This is complicated by the fact that the high double
-         may already be rounded and the low double may have the
-         opposite sign to compensate.  */
-      if (u.dd[0] > 0.0)
-	{
-	  if (u.dd[1] > 0.0)
-	    {
-	      /* If the high/low doubles are the same sign then simply
-	         round the low double.  */
-	      high = u.dd[0];
-	      low = u.dd[1];
-	    }
-	  else if (u.dd[1] < 0.0)
-	    {
-	      /* Else the high double is pre rounded and we need to
-	         adjust for that.  */
-	      high = nextafter (u.dd[0], 0.0);
-	      low = u.dd[1] + (u.dd[0] - high);
-	    }
-          fesetround(FE_DOWNWARD);
-	  low += TWO52;
-	  low -= TWO52;
-	}
-      else if (u.dd[0] < 0.0)
-	{
-	  if (u.dd[1] < 0.0)
-	    {
-	      /* If the high/low doubles are the same sign then simply
-	         round the low double.  */
-	      high = u.dd[0];
-	      low = u.dd[1];
-	    }
-	  else if (u.dd[1] > 0.0)
-	    {
-	      /* Else the high double is pre rounded and we need to
-	         adjust for that.  */
-	      high = nextafter (u.dd[0], 0.0);
-	      low = u.dd[1] + (u.dd[0] - high);
-	    }
-          fesetround(FE_DOWNWARD);
-	  low -= TWO52;
-	  low += TWO52;
-	}
-      fesetround(mode);
-      u.dd[0] = high + low;
-      u.dd[1] = high - u.dd[0] + low;
+      int save_round = fegetround ();
+
+      /* Long double arithmetic, including the canonicalisation below,
+	 only works in round-to-nearest mode.  */
+      fesetround (FE_TONEAREST);
+
+      /* Convert the high double to integer.  */
+      hi = ldbl_nearbyint (xh);
+
+      /* Subtract integral high part from the value.  */
+      xh -= hi;
+      ldbl_canonicalize (&xh, &xl);
+
+      /* Now convert the low double, adjusted for any remainder from the
+         high double.  */
+      lo = ldbl_nearbyint (xh);
+
+      /* Adjust the result when the remainder is non-zero.  nearbyint
+         rounds values to the nearest integer, and values halfway
+         between integers to the nearest even integer.  floorl must
+         round towards -Inf.  */
+      xh -= lo;
+      ldbl_canonicalize (&xh, &xl);
+
+      if (xh < 0.0 || (xh == 0.0 && xl < 0.0))
+	lo += -1.0;
+
+      /* Ensure the final value is canonical.  In certain cases,
+         rounding causes hi,lo calculated so far to be non-canonical.  */
+      xh = hi;
+      xl = lo;
+      ldbl_canonicalize (&xh, &xl);
+
+      fesetround (save_round);
     }
 
-  return u.d;
+  return ldbl_pack (xh, xl);
 }
 
 long_double_symbol (libm, __floorl, floorl);
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_rintl.c b/sysdeps/ieee754/ldbl-128ibm/s_rintl.c
index 51b1fea2c4..1f4e33f91c 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_rintl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_rintl.c
@@ -22,6 +22,7 @@
    when it's coded in C.  */
 
 #include <math.h>
+#include <fenv_libc.h>
 #include <math_ldbl_opt.h>
 #include <float.h>
 #include <ieee754.h>
@@ -36,84 +37,83 @@ __rintl (x)
      long double x;
 #endif
 {
-  static const long double TWO52 = 4503599627370496.0L;
-  union ibm_extended_long_double u;
-  u.d = x;
+  double xh, xl, hi, lo;
 
-  if (fabs (u.dd[0]) < TWO52)
-    {
-      double high = u.dd[0];
-      if (high > 0.0)
-	{
-	  high += TWO52;
-	  high -= TWO52;
-          if (high == -0.0) high = 0.0;
-	}
-      else if (high < 0.0)
-	{
-	  high -= TWO52;
-	  high += TWO52;
-          if (high == 0.0) high = -0.0;
-	}
-      u.dd[0] = high;
-      u.dd[1] = 0.0;
-    }
-  else if (fabs (u.dd[1]) < TWO52 && u.dd[1] != 0.0)
+  ldbl_unpack (x, &xh, &xl);
+
+  /* Return Inf, Nan, +/-0 unchanged.  */
+  if (__builtin_expect (xh != 0.0
+			&& __builtin_isless (__builtin_fabs (xh),
+					     __builtin_inf ()), 1))
     {
-      double high, low, tau;
-      /* In this case we have to round the low double and handle any
-         adjustment to the high double that may be caused by rounding
-         (up).  This is complicated by the fact that the high double
-         may already be rounded and the low double may have the
-         opposite sign to compensate.  */
-      if (u.dd[0] > 0.0)
-	{
-	  if (u.dd[1] > 0.0)
-	    {
-	      /* If the high/low doubles are the same sign then simply
-	         round the low double.  */
-	      high = u.dd[0];
-	      low = u.dd[1];
-	    }
-	  else if (u.dd[1] < 0.0)
-	    {
-	      /* Else the high double is pre rounded and we need to
-	         adjust for that.  */
-	      
-	      tau = nextafter (u.dd[0], 0.0);
-	      tau = (u.dd[0] - tau) * 2.0;
-	      high = u.dd[0] - tau;
-	      low = u.dd[1] + tau;
-	    }
-	  low += TWO52;
-	  low -= TWO52;
-	}
-      else if (u.dd[0] < 0.0)
+      double orig_xh;
+      int save_round = fegetround ();
+
+      /* Long double arithmetic, including the canonicalisation below,
+	 only works in round-to-nearest mode.  */
+      fesetround (FE_TONEAREST);
+
+      /* Convert the high double to integer.  */
+      orig_xh = xh;
+      hi = ldbl_nearbyint (xh);
+
+      /* Subtract integral high part from the value.  If the low double
+	 happens to be exactly 0.5 or -0.5, you might think that this
+	 subtraction could result in an incorrect conversion.  For
+	 instance, subtracting an odd number would cause this function
+	 to round in the wrong direction.  However, if we have a
+	 canonical long double with the low double 0.5 or -0.5, then the
+	 high double must be even.  */
+      xh -= hi;
+      ldbl_canonicalize (&xh, &xl);
+
+      /* Now convert the low double, adjusted for any remainder from the
+	 high double.  */
+      lo = ldbl_nearbyint (xh);
+
+      xh -= lo;
+      ldbl_canonicalize (&xh, &xl);
+
+      switch (save_round)
 	{
-	  if (u.dd[1] < 0.0)
-	    {
-	      /* If the high/low doubles are the same sign then simply
-	         round the low double.  */
-	      high = u.dd[0];
-	      low = u.dd[1];
-	    }
-	  else if (u.dd[1] > 0.0)
-	    {
-	      /* Else the high double is pre rounded and we need to
-	         adjust for that.  */
-	      tau = nextafter (u.dd[0], 0.0);
-	      tau = (u.dd[0] - tau) * 2.0;
-	      high = u.dd[0] - tau;
-	      low = u.dd[1] + tau;
-	    }
-	  low = TWO52 - low;
-	  low = -(low - TWO52);
+	case FE_TONEAREST:
+	  if (xl > 0.0 && xh == 0.5)
+	    lo += 1.0;
+	  else if (xl < 0.0 && -xh == 0.5)
+	    lo -= 1.0;
+	  break;
+
+	case FE_TOWARDZERO:
+	  if (orig_xh < 0.0)
+	    goto do_up;
+	  /* Fall thru */
+
+	case FE_DOWNWARD:
+	  if (xh < 0.0 || (xh == 0.0 && xl < 0.0))
+	    lo -= 1.0;
+	  break;
+
+	case FE_UPWARD:
+	do_up:
+	  if (xh > 0.0 || (xh == 0.0 && xl > 0.0))
+	    lo += 1.0;
+	  break;
 	}
-      u.dd[0] = high + low;
-      u.dd[1] = high - u.dd[0] + low;
+
+      /* Ensure the final value is canonical.  In certain cases,
+         rounding causes hi,lo calculated so far to be non-canonical.  */
+      xh = hi;
+      xl = lo;
+      ldbl_canonicalize (&xh, &xl);
+
+      /* Ensure we return -0 rather than +0 when appropriate.  */
+      if (orig_xh < 0.0)
+	xh = -__builtin_fabs (xh);
+
+      fesetround (save_round);
     }
 
-  return u.d;
+  return ldbl_pack (xh, xl);
 }
 
 long_double_symbol (libm, __rintl, rintl);
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_roundl.c b/sysdeps/ieee754/ldbl-128ibm/s_roundl.c
index 7fe84b87de..0880e6ee22 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_roundl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_roundl.c
@@ -22,7 +22,7 @@
    when it's coded in C.  */
 
 #include <math.h>
-#include <fenv.h>
+#include <fenv_libc.h>
 #include <math_ldbl_opt.h>
 #include <float.h>
 #include <ieee754.h>
@@ -37,84 +37,62 @@ __roundl (x)
      long double x;
 #endif
 {
-  static const double TWO52 = 4503599627370496.0;
-  static const double HALF = 0.5;
-  int mode = fegetround();
-  union ibm_extended_long_double u;
-  u.d = x;
-
-  if (fabs (u.dd[0]) < TWO52)
-    {      
-      fesetround(FE_TOWARDZERO);
-      if (u.dd[0] > 0.0)
-	{
-	  u.dd[0] += HALF;
-	  u.dd[0] += TWO52;
-	  u.dd[0] -= TWO52;
-	}
-      else if (u.dd[0] < 0.0)
-	{
-	  u.dd[0] = TWO52 - (u.dd[0] - HALF);
-	  u.dd[0] = -(u.dd[0] - TWO52);
-	}
-      u.dd[1] = 0.0;
-      fesetround(mode);
-    }
-  else if (fabs (u.dd[1]) < TWO52 && u.dd[1] != 0.0)
+  double xh, xl, hi, lo;
+
+  ldbl_unpack (x, &xh, &xl);
+
+  /* Return Inf, Nan, +/-0 unchanged.  */
+  if (__builtin_expect (xh != 0.0
+			&& __builtin_isless (__builtin_fabs (xh),
+					     __builtin_inf ()), 1))
     {
-      double high, low;
-      /* In this case we have to round the low double and handle any
-         adjustment to the high double that may be caused by rounding
-         (up).  This is complicated by the fact that the high double
-         may already be rounded and the low double may have the
-         opposite sign to compensate.  */
-      if (u.dd[0] > 0.0)
+      double orig_xh;
+      int save_round = fegetround ();
+
+      /* Long double arithmetic, including the canonicalisation below,
+	 only works in round-to-nearest mode.  */
+      fesetround (FE_TONEAREST);
+
+      /* Convert the high double to integer.  */
+      orig_xh = xh;
+      hi = ldbl_nearbyint (xh);
+
+      /* Subtract integral high part from the value.  */
+      xh -= hi;
+      ldbl_canonicalize (&xh, &xl);
+
+      /* Now convert the low double, adjusted for any remainder from the
+	 high double.  */
+      lo = ldbl_nearbyint (xh);
+
+      /* Adjust the result when the remainder is exactly 0.5.  nearbyint
+	 rounds values halfway between integers to the nearest even
+	 integer.  roundl must round away from zero.
+	 Also correct cases where nearbyint returns an incorrect value
+	 for LO.  */
+      xh -= lo;
+      ldbl_canonicalize (&xh, &xl);
+      if (xh == 0.5)
 	{
-	  if (u.dd[1] > 0.0)
-	    {
-	      /* If the high/low doubles are the same sign then simply
-	         round the low double.  */
-	      high = u.dd[0];
-	      low = u.dd[1];
-	    }
-	  else if (u.dd[1] < 0.0)
-	    {
-	      /* Else the high double is pre rounded and we need to
-	         adjust for that.  */
-	      high = nextafter (u.dd[0], 0.0);
-	      low = u.dd[1] + (u.dd[0] - high);
-	    }     
-          fesetround(FE_TOWARDZERO);
-	  low += HALF;
-	  low += TWO52;
-	  low -= TWO52;
+	  if (xl > 0.0 || (xl == 0.0 && orig_xh > 0.0))
+	    lo += 1.0;
 	}
-      else if (u.dd[0] < 0.0)
+      else if (-xh == 0.5)
 	{
-	  if (u.dd[1] < 0.0)
-	    {
-	      /* If the high/low doubles are the same sign then simply
-	         round the low double.  */
-	      high = u.dd[0];
-	      low = u.dd[1];
-	    }
-	  else if (u.dd[1] > 0.0)
-	    {
-	      /* Else the high double is pre rounded and we need to
-	         adjust for that.  */
-	      high = nextafter (u.dd[0], 0.0);
-	      low = u.dd[1] + (u.dd[0] - high);
-	    }     
-          fesetround(FE_TOWARDZERO);
-	  low -= HALF;
-	  low = TWO52 - low;
-	  low = -(low - TWO52);
+	  if (xl < 0.0 || (xl == 0.0 && orig_xh < 0.0))
+	    lo -= 1.0;
 	}
-      fesetround(mode);
-      u.dd[0] = high + low;
-      u.dd[1] = high - u.dd[0] + low;
+
+      /* Ensure the final value is canonical.  In certain cases,
+	 rounding causes hi,lo calculated so far to be non-canonical.  */
+      xh = hi;
+      xl = lo;
+      ldbl_canonicalize (&xh, &xl);
+
+      fesetround (save_round);
     }
-  return u.d;
+
+  return ldbl_pack (xh, xl);
 }
 
 long_double_symbol (libm, __roundl, roundl);
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_truncl.c b/sysdeps/ieee754/ldbl-128ibm/s_truncl.c
index 14544af206..d7bc47ee0d 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_truncl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_truncl.c
@@ -22,7 +22,7 @@
    when it's coded in C.  */
 
 #include <math.h>
-#include <fenv.h>
+#include <fenv_libc.h>
 #include <math_ldbl_opt.h>
 #include <float.h>
 #include <ieee754.h>
@@ -37,83 +37,66 @@ __truncl (x)
      long double x;
 #endif
 {
-  static const double TWO52 = 4503599627370496.0L;
-  int mode = fegetround();
-  union ibm_extended_long_double u;
+  double xh, xl, hi, lo;
 
-  u.d = x;
+  ldbl_unpack (x, &xh, &xl);
 
-  if (fabs (u.dd[0]) < TWO52)
-    {      
-      fesetround(FE_TOWARDZERO);
-      if (u.dd[0] > 0.0)
-	{
-	  u.dd[0] += TWO52;
-	  u.dd[0] -= TWO52;
-	}
-      else if (u.dd[0] < 0.0)
-	{
-	  u.dd[0] = TWO52 - u.dd[0];
-	  u.dd[0] = -(u.dd[0] - TWO52);
-	}
-      u.dd[1] = 0.0;
-      fesetround(mode);
-    }
-  else if (fabs (u.dd[1]) < TWO52 && u.dd[1] != 0.0)
+  /* Return Inf, Nan, +/-0 unchanged.  */
+  if (__builtin_expect (xh != 0.0
+			&& __builtin_isless (__builtin_fabs (xh),
+					     __builtin_inf ()), 1))
     {
-      double high, low;
-      /* In this case we have to round the low double and handle any
-         adjustment to the high double that may be caused by rounding
-         (up).  This is complicated by the fact that the high double
-         may already be rounded and the low double may have the
-         opposite sign to compensate.  */
-      if (u.dd[0] > 0.0)
+      double orig_xh;
+      int save_round = fegetround ();
+
+      /* Long double arithmetic, including the canonicalisation below,
+	 only works in round-to-nearest mode.  */
+      fesetround (FE_TONEAREST);
+
+      /* Convert the high double to integer.  */
+      orig_xh = xh;
+      hi = ldbl_nearbyint (xh);
+
+      /* Subtract integral high part from the value.  */
+      xh -= hi;
+      ldbl_canonicalize (&xh, &xl);
+
+      /* Now convert the low double, adjusted for any remainder from the
+         high double.  */
+      lo = ldbl_nearbyint (xh);
+
+      /* Adjust the result when the remainder is non-zero.  nearbyint
+         rounds values to the nearest integer, and values halfway
+         between integers to the nearest even integer.  floorl must
+         round towards -Inf.  */
+      xh -= lo;
+      ldbl_canonicalize (&xh, &xl);
+
+      if (orig_xh < 0.0)
 	{
-	  if (u.dd[1] > 0.0)
-	    {
-	      /* If the high/low doubles are the same sign then simply
-	         round the low double.  */
-	      high = u.dd[0];
-	      low = u.dd[1];
-	    }
-	  else if (u.dd[1] < 0.0)
-	    {
-	      /* Else the high double is pre rounded and we need to
-	         adjust for that.  */
-	      high = nextafter (u.dd[0], 0.0);
-	      low = u.dd[1] + (u.dd[0] - high);
-	    }      
-          fesetround(FE_TOWARDZERO);
-	  low += TWO52;
-	  low -= TWO52;
-          fesetround(mode);
+	  if (xh > 0.0 || (xh == 0.0 && xl > 0.0))
+	    lo += 1.0;
 	}
-      else if (u.dd[0] < 0.0)
+      else
 	{
-	  if (u.dd[1] < 0.0)
-	    {
-	      /* If the high/low doubles are the same sign then simply
-	         round the low double.  */
-	      high = u.dd[0];
-	      low = u.dd[1];
-	    }
-	  else if (u.dd[1] > 0.0)
-	    {
-	      /* Else the high double is pre rounded and we need to
-	         adjust for that.  */
-	      high = nextafter (u.dd[0], 0.0);
-	      low = u.dd[1] + (u.dd[0] - high);
-	    }      
-          fesetround(FE_TOWARDZERO);
-	  low = TWO52 - low;
-	  low = -(low - TWO52);
-          fesetround(mode);
+	  if (xh < 0.0 || (xh == 0.0 && xl < 0.0))
+	    lo -= 1.0;
 	}
-      u.dd[0] = high + low;
-      u.dd[1] = high - u.dd[0] + low;
+
+      /* Ensure the final value is canonical.  In certain cases,
+         rounding causes hi,lo calculated so far to be non-canonical.  */
+      xh = hi;
+      xl = lo;
+      ldbl_canonicalize (&xh, &xl);
+
+      /* Ensure we return -0 rather than +0 when appropriate.  */
+      if (orig_xh < 0.0)
+	xh = -__builtin_fabs (xh);
+
+      fesetround (save_round);
     }
 
-  return u.d;
+  return ldbl_pack (xh, xl);
 }
 
 long_double_symbol (libm, __truncl, truncl);